Devices of this kind exist on the market, in particular consisting of a male element and of a female element, wherein at least one of these two elements provides spring-type fastening means, in order to allow the mutual snap engagement, disengageable only by imparting a disengagement force by the operator.
Thus-made prior art structures, useful as they may be, often prove cumbersome, requiring special attention in the manufacturing step, since these devices are of a small size and in extreme environmental conditions may experience jamming, as well as during the installation step, since special attention is needed when recording the mutual position of the various elements.